Building the Realtime User Experience

Responding Intelligently

At this point, we’re receiving messages and sending back simple output. Let’s take some time to examine the data as it comes in and respond to it. We’ll allow the user to enter simple commands to our application and respond appropriately to the request.

The Basic Commands

We’re going to expand this application to accept basic commands and respond with the appropriate response. To do this, we must first understand the command format. To keep it simple, we’ll assume that any instant message that we receive is a command. The first word of that message is the command itself, and the rest of string represents any additional parameters for the command.

Let’s start by parsing out the command itself from the rest of the message. Add the following code to your XMPPHandler class:

class XMPPHandler(BaseHandler):
    def post(self):
        message = xmpp.Message(self.request.POST)
        logging.info("XMPP sender: %s - body: %s" % (message.sender, message.body))
        # The command from the user
        cmd = message.body.split(' ')[0].lower()
        # the rest of the message
        body = message.body[len(cmd) + 1:]

Because the format is command and the rest of the string, to parse out the command, we simply need to grab anything before the first space character. We then convert it to lowercase to make it easier to match in the next step, which determines what we do with each command. Keep adding to that method:

 # echo the data back to the client if cmd == 'echo': message.reply(body) # convert string to rot13 and ...